I'm Sure you have noticed that on
extended motorway driving, or long days working hard "offroad" the heat
that can be "felt" coming from the tunnel area inside the car is quite
significant. This comes mostly from the transfer box as its continually
working while the vehicle is in use, I still find it a little strange how
the box has no "factory" cooling system installed like the Auto box etc.

I'm aware it does or "should" not get
up to auto box temperatures during normal use, but some cooling in my
opinion would be a good thing, it would not only extend the "life" of the
oil, but should in turn as a direct result extend the life of the internal
parts of the transfer box. Disco 2's in the NAS and Jap markets have an
additional gearbox temp switch fitted in them which is wired up to the
dashboard over temp light as used by the Auto box models, why they all
don't have it who knows!!

This switch for whatever reason is
never fitted to UK spec vehicles, I'm not saying its "needed" in all
cases, but you never have any idea if your "over temping" your transfer
box oil or not.......this may be more relevant to vehicles with chipped
engines and modified drive trains as all these factors will affect the
temp of the transfer box during either on road or offroad use..

With this in mind, and the fact I
still fully intend to head to a hotter climate to "play" one day, adding
some "protection" to the transfer box would definitely be a worthwhile
modification. One product to help with this issue I really liked was the
extended capacity "cooling" sump for the LT230 made by Roverdrives in
Canada.

This is a simple bolt on solution for
the LT230 box fitted to Discovery 2's, it also fits previous models that
use the LT230 transfer case. It simply
replaces the existing bottom cover on the transfer case and as well as
having the "cooling fins" cast into it, it actually increases the capacity
of the oil by about another 3/4 of a litre, which again can only be a good
thing as more oil will "absorb" more heat and if its being cooled as well
its serviceable life will be extended.

You may also notice from the above
picture that it has a "blank" where you can if you wish drill and tap the
sump to add your own additional temperature switch.

To install the sump I removed the
FWD cross member from underneath the transfer box to make it easier to fit the
sump, I think you could probably do it without removing it, but its far
easier out the way.

NOTE !!! These bolts are often VERY
corroded and will shear off if to much force is applied.......I "felt" a
couple when first attacking the job and they did not move straight
away......so with that in mind I heated ALL of them with a blow torch in
turn and used lots of penetrating fluid before attempting to undo them.
Fortunately they all came out and I feel it was most likely the heat of
the blow torch that did the trick. You may well find some of yours have
all ready been replace with nuts and bolts because they have been sheared
in the past, whatever your situation if your not "prepped" for a fight,
then it may well be a wise choice to install the new sump without removing
the cross member. I STRONGLY recommend the use of 6 point sockets for this
job.

Once the cross member
was off I then drained the oil as per the
transfer box
boxoil replacement page. Next you simply unbolt the lower transfer box cover,
then carefully clean up the mating surface ready for the new sump.

It was also nice to have a little nosy inside the
transfer box to have a look at the condition of the gears etc in there.
It's certainly not possible to check it all
out, but from what I could see there was no obvious wear or damage on any of the
gears in view, which I was quite happy about.

The new sump comes with a gasket, some thread lock and
10 nice new shiny stainless cap head bolts and washers. The original cover
is / was not installed with a gasket, it is simply RTV'd on.....I could
not decide which was best, so I used the new paper gasket and a fine smear
of RTV on the bottom of the transfer case. Only time will tell if it leaks
or not, but to date (300 miles) its still leak free.

Use the thread lock supplied with the kit and install
all 10 bolts hand tight first, then tighten / torque to 18Lbs ft in an
opposing manner to pull the sump on evenly.

Refit the cross member (if removed) and tighten / torque
the bolts to 26NM or 19Lbs ft. Its a VERY good idea to install the cross
member bolts soaked with an anti-seize grease to stop them corroding in
the future to aid removal further down the line with out the need
for a blow torch again!!. Once the sump is installed, simply refill as per
the transfer
box servicing page noting you will now need up to 3 litres of oil due
to the extended capacity.

Overall a very nice product and I hope it does as much good as it looks!!.